C-31 or Eix Costaner is one of Catalonia's primary highways. It is the result of merging several sections of previously existing roads, autopistas and autovías after the 2004's renaming of primary highways managed by the Generalitat de Catalunya. According to this new denomination, the first number (C-31) indicates that is a southwest-northeast highway (parallel to the Mediterranean Sea coastline), while the second number (C-31) indicates that is the closest to the Mediterranean Sea.[1][2]
Southern section (El Vendrell-South Barcelona)
The C-31's southern section has two clearly distinguished subsections:
This C-31's section corresponds to a part of the former A-19autopista, also known as Autopista del Maresme, which was the first autopista ever in Spain (1969). It starts at Barcelona's Plaça de les Glòries and runs parallel to the coastline passing through the city of Badalona and finishing at the intersection with the B-20 and the C-32, at Montgat.
This highway section should continue over the actual N-II, at the comarca of Maresme, but since this road is managed by the Spanish government, it has not been renamed yet.
Costa Brava's section (Santa Cristina d'Aro-Figueres)